Overload release clutch



' Marh 2,1948. l

P. L( A.AVERGNE ovERLoAD` RELEAgE CLUTCH l Filed Feb.. 2.` 1945 Sheets-Sheet 1 INVENTOR March 2, P. 1.. A. AVERGNE 2,436,947

OVERLOAD RELEASE CLUTCH mvENroRv4 l PIERRE Louis Patented Mar. 2, 1948 ovERLoAD RELEASE CLUTCH Pierre Louis ndrVergne; Saint-Cloud, France, assigner to Socit Elox, Courbevoie, France,

a society of France Application February 2, 1945, Serial No. 5vi5,86.72v Y In France November V23,1943

The presentv invention relates to dynamometric devices yof the kind usedfoiz measuring, adjusting or limiting the `eiiortapplied to a part or system of parts, and in. particular toashaft or other rotary element. It, s more especially, although not exclusively, concerned, among .these devices, with those lto be .interposed between two rotary members for producinganautomaticdisengagement (or any otherdesiredaction) as soon as. the. torque transmittedqiromone f these memberstd the otherexceedsa given value.

The chief object of this invention is tolprovide a device oithetype `above described which ris better .adaptedtp meet the requirements of practice than thoseused-for the same purpose up to the pr esen t"time an d, `in particular, which is sim pler andleasierto adjust. Other objects @f rnirimeniion Willapnear from the followingdetailed description of some spe- -cie embodiments thereof.

Preferredenibodiments of the present invention will be hereinafter describedwith reference to the accomnanyng drawines, given merely, by wawf example-and which: v i Fig. 1 is a sectional vieu/transverse to the axis of the device, o f auto-matic disengagement means made according toanrst einbodiment v of, the presentnveotiom Fig. 2 is a transversesectional 4view of another embodiment of adevice of thesamekind made according to second embodiment ofthe invention, with means for controlling from a distance the reengagement of the parts;

Fig 3 is an axial sectional View corresponding to Fig. 2

In the followingdescription it will be supfgroupsbeing carried by a disc 3 xed on one of the shafts, to wit vA (which is supposed in this case to be the driven shaft) b.Y On the other hand, for transmitting to pistons v2, or t-o the rods 4 of these pistons, an eiort 'F whichv is a `function Aof torque C; clutch means Vconsistingjor instanceof pawls or cams 5 pivoted` atG to disc and to each of which the torque C is transmitted at'I. This torqueis imparted by an element rigid Vwith the driving part or member of'lthe'devicaior vinstance by the edge of anotch 1 1 Claims. (Cl. 192-56) 8 provided in member In this example, mem-V ber B is supposed to be constituted by'a'n annular part carried by a driving shaft or other rotary member (for instance a shaft''as shown by/Fig. 3). The portion IEE of pawl 5 serves to trans'rdnit effort F to the rod 4 of piston 2; and, nal ly,

c. One or several discharge means vadapted'to open only when the limit 'pressurehas' been reached. These means are for instance consti; tuted by avalve'li subjectedtothe action b'f a spring I2v and which ooacts with conduits I4, `'I5 Yand I3 leading tocylinders'I, Q-The'whlolje is arf ranged in such mannerthatjwhen the pressure P existing in said cylinders eicleedsV agiven value, this valve opens andallows the liquidto escape either Vinto a suitable casing provided aioiind 'the -device or toward aretu'rn conduit, as'it will" moreA specifically described with reference to Figs. 2ald3- I f With such an arrangement, intheoutline "of Canis or claws has beensuitably determindfs'o that these cams or pawls can retractfirisideannular member B when torqueC vreaches itsliinit value and causesft'he liquid 'to Ybe discharged 'through valve il, a disengagement of parte Aan'd provided in annularmemberBiiio'lohger transl mit any movement to the corresponding portions oisaidcams or pawls. w

Undernor lal working conditions(*thecamsVA 'or pawls may be urged byfelastic nieaisv toward their positions @f ehgag'enientivitl said^dges1- Said elastic means are, in the embodiment illustrated by the drawing, vc'onstitu'tedY by'aspring i5 which tends to bring the cams lor"'p'aivls into contact with an abutment I Furthermore. ymeans"Infayfloe 'provided fo'i' permitting the adjustment ci tnev'aiueof theiiinit torque to be transmitted. These meansfoperate by varying the reaction opposed t vtheopen'rig of valve II.v In the embodimentillustrate'dfthey are therefore means'V vforadjusting the strength of-sp-ring I2, and arefor` instance constituted by an adjustable abutment I8 for sai'dsplri'n'g;

It must also'be'possiblefafter the'loartsA or members A rand'B havev been" disconnectedftorell cylinders I Vwith liduid so "asto permitof bringingl back 'intO its initial Statefl'i Whihssad partsare driven-one l'oythe'other'.l

The refilling of c y1inders I with -liqu'idcanbe performed: either through manually v-operated 'means provided on the device itself; 'or through means operable lfrom a distance, 'and'whichhiay eventually be automatic. 'In Eig. 1,7 Ihave shown aV device for the 'llin'g 3 of the cylinders and carried by disc 3. This nlling device is constituted by filling check valve I9 adapted, once plug has been removed, to be opened by the end of a syringe or equivalent instrument inserted into an orice such as 2 I The liquid from said lling instrument is thus forced into a body 22 in communication with conduits I4 and l5. Check valve I9, guided at 23, is subjected to the action of a spring 24 which auto?` matically closes it as soon as thev Ven ,dvof the syringe or equivalent instrument is Withdrawn.

Figs. 2 and 3 show another embodiment-of the invention in which the discharge and lling means are operable from a distance. Said means include a distributing element, constituted by a slide valve 25, controlling two conduits 26'a'nd 21 serving respectively to the dischargeand the feed of liquid. This liquid is, for instance 'supe plied by the lubricating oil system.

It results from the drawings that, in the position of distributing member that is illustrated by Fig. 3, the liquid can be freely discharged, when the maximum torque is reached, through conduits 29, 3l and 2B.

In order to reengage the parts into their initial position, the distributing member is displaced in such manner as to close the discharge conduit and to permit the feed of fresh liquid through conduit 21 into conduits 30 and 33. and, consequently, into the cylinders l of the device.

It should be well understood that I might combine with a device such as that just above described means for causing the liquid to play a part different from that above set forth, and

eventually a supplementary part, for instance f that' of facilitating the starting of the whole. For this purpose, in order to avoid too sudden'a starting of the driven parts, I may provide in the body of the apparatus elastic means such as an air cushion capable of absorbing shocks owing to the possibility of slight relative displacement of pistons 2 for short time periods.

Finally, it is clear that several devices such as above described may be combined together, provided that the pressures in the respective cylinl ders are balanced by the provision of interconnecting conduits extending between said devices.

Anyway, whatever be the particular embodiment that is chosen, I obtain a device the operation of which results sufficiently clearly from the preceding description for making it unnecessary to enter into further explanations. v

This device has, over those employedfor ,the

same purpose prior to the present invention,

many advantages among which the following are believed to be particularly interesting:

The device according to this invention permits an easy adjustment of the limit effort to be supported by the parts;

It includes only simple elements which can easily be replaced when necessary.

Such a device is adapted to a great number of different applications. It may be used, for instance, as a torque limiting device or an automatic disconnecting device for use in connection with machine-tools or other apparatus.

It may also be used for adjusting the `resisting torque applied to engine shafts, for instance Ipropeller shafts.

The device according to the present invention can also be used when it is desired, not to disconnect two rotary members normally driven one by the other, but to adjust-the relative angular kpositions of these two members in accordance,

for instance, with the efforts supported by one and e'iiicient' embodiments of the present invention, itshouldbe well understood that I vdo not wisnnto be limited Vthereto as there might be changes 'made the arrangement, disposition and form of. the parts without departing from the" principle of the0 present invention as compreh-en'de'dlwithin the scope of the appended claims.

What Iclaim is:

1. A device of the type described which come prises, in combination, two coaxial rotary members adapted to be driven one by the'other, at least one clutch pawl movably carried by one of said members for coupling it with the other', said pawl being pivoted to said rst mentioned member about an axisparallel to the rotation axis thereofso that, in its position of engagement with saidsecond mentioned member, it is urged toward ,its disengaged, position by the torque transmitted through itself from one member to the other, an abutment carried by sai-d rst mentioned member for limiting the rotation of said pawlfabout its axis to its position of engagement with said second mentioned member, spring means .for urging vsaid pawl toward said abutment,.a hydraulic jack including a cylinder carried by said first mentionedpmember at right angles to said rotation axis, a piston slidable in lsai-d cylinder, and a rod carried by said piston and in contact with said pawl, said rodbeing adapted, in thel expanded position of said jack to VVcooperate with said pawl for holding it in engaged position Vwhile transmitting, in series therewith, the torque thrust from one member .to `the.otherand a loaded discharge valve for .said jack carried by said .rst mentioned member adapted to open in vresponse to a rise of the liquid pressure in ysaid cylinder above a given value,thus permitting said pawl to be forced into disengaged position by any torque to be trans- `rnitted therethrough ,that exceeds a given value.

2 A ,device of the type described which comprisesjin combination, two coaxial rotary mem- ,bers adapted to be.driven one by they other, at

least two mechanical clutch means movablycar ried by one c-f said members for coupling it with theother, said clutch means beingso mounted on said first mentioned member that, in their position of engagement with said second mentioned member, they are urged towardgtheir disengaged position bythe torque transmitted through them lfrom one membertothe other, at least two fluid j-acl; meansincluding each at least one cylinder rigid with said first mentioned member and at `leastone piston slidable insaid cylinder, said pisfon said chamber carriedby said Afirst:mentioned member adaptedto'openin/response'to a rise of the liquid pressure in said cylinders and chamber `above a ygiven value, thus permitting said clutch means to be forced into disengaged position by any torque to be transmitted that exceeds a given value, and check valve means in communication with' said cylinders, carried by said rst mentioned member, for the reiilling of said cylinders after a discharge of liquid therefrom, whereby said clutch means can be restored into engagement with said second mentioned member.

3. A devicecf the type described which comprises, in combination, two coaxial rotary members adapted to be driven one by the other, mechanical clutch means movably carried by one of said members for coupling it with the other, said clutch means being so mounted on said rst mentioned member that, in their position of engagement with said seco-nd mentioned member,

vthey are urged toward their disengaged position by the torque transmitted through them from one member to the other, hydraulic jack means including at least one cylinder carried by said first mentioned member and at least one piston slidable in said cylinder, said piston being adapted, in the expanded position of said jack means, to cooperate with said clutch means for holding them in engaged position while transmitting, in series therewith, the torque thrust from one member to the other, a loeded'discharge valve for said jack means carried by said rst mentioned member adapted to open in response to a rise of the liquid pressure in said cylinder above a given value, thus permitting said clutch means to be forced into disengaged position by any torque to be transmitted that exceeds a given Value, a discharge conduit carried by said first mentioned member and in communication with the output side of said valve, a conduit adapted to be connected with a source of liquid under pressure carried by said iirst mentioned member and in communicationwith said cylinder, and distributing mea-,ns for alternately cutting off one of said conduits and the other,

4. A device of the type described which comprises, combination', two coaxial :rotary members adapted to be driven by the other, at

kleast two mechanical clutch means movably carried by one of members for coupling it with the other, said clutch means being so mounted on said @rst mentioned member that, in their position of engagement with said second mentioned member, they are urged toward their disengaged position by the torque transmitted through them from one member to the other, at least two fluid jack means including each at least one cylinder rigid with said first mentioned member and at least one piston slidable in said cylinder, said piston being adapted, in the expanded position of said jack means, to cooperate with one of said clutch means respectively for holding said clutch means in engaged position while transmitting, in series therewith, the torque thrust from one member to the other, means carried by said first mentioned member forming a hollow chamber in communication with said jack means cylinders and also filled with liquid, a loaded discharge valve for said chamber carried by said rst mentioned member adapted to open in response to a rise of the liquid pressure in said cylinders and chamber abo-ve a given value, thus permittingsaid clutch'means to be forced into disengaged position by any torque to be transmitted that exceeds a given value, a discharge conduit carried by said Erst mentioned member and in communication with the output side of said valve,

a conduit adapted to be connected with'a source of; liquidi under .pressure '.carried' by said- Afirst mentioned member and in communication with said cylinders' and distributing. means .for alternately cutting orf one ofsaid .conduits and opening the other.

5. Adevice'of the type described whichcomprises, in combination,""two vcoaxial rotary members i adapted 'to fbe driven one'by the other, at least one clutch clawmcvablyicarriedby one of said members for copling'it'withthe other, said claw being pivoted to said'rst'mentioned member aboutan axis parallel to the rotation' axis thereof -so that, in its position. of engagement with said second mentioned member, it is urged toward its .disengaged position by the torque transmitted through itself from one memberto the other', ahydraulic'jack including" a cylinder carried by said rst mentioned member'at right angles. to said rotationA a piston slidable in said cylinder, and a rodcarried byv said piston and in contact with saidclaw, said rod being adapted, in the expanded position-of Asaid jack, to cooperate with said claw forV holding it in engaged position while transmitting,in series therewith, the torque thrust from onemember tothe other, a loaded dischargevalve for said jack carried by said a'st mentioned member .adapted vto open in response Vto a rise of the liquid pressure in said cylinder-above agiVen-value, thus permitting said claw to bev forced rintodisengaged position byk any torque to be transmitted therethrough that exceeds ,a'given value, a discharge conduit-carried by said rst mentioned member and in communication with the output side of said valve, a conduit adapted to'be connected with a source of liquid under-pressure carried by said Iirst mentioned memberv and in communication with said cylinder, and distributingmeans for alternately cutting off one of said conduits and opening the other. Y l Y 6. A device of the type` described whichcomprises, in combination, two coaxial rotary members adapted tobe driven one by the other,' at least two clutch-claws movablyV carried-by one of said members Afor coupling it with theV other, each of said claws being pivoted -tosaid first mentioned member about-anaxis parallelto the rotation axis thereof so that, in Yits position of engagementwith said` second mentioned member, it is urged toward its disengaged position by they torque transmitted through itself-from one member to the other, at least two hydraulicjaclrs including each a cylinder carried Yby said vlrlrst mentioned member at right anglesl to said rotation axis, a piston slidable-insaid cylinder, and a vrod carried by said piston and in contact with one of said claws respectively,-said rod being adapted, in the expanded position ofY said jack, to cooperate with the corresponding claw `for holding it in engaged position while,Y transmitting, in series therewith, the torque thrust from one member to the other, means carried by said rst mentioned member forming a hollow chamber in communication with -said `jack cylinders and also full of liquid, a spring-loaded discharge valve for' said chamber carried bysaid rst mentioned member adapted to open in responsev to a rise of the liquid pressure in said cylinders and chamber above a given value, thus permitting Vsaid claw to be forced into disengaged position by any torque to be transmittedtherethrough that exceeds a given value, a discharge conduit carried by said rst mentioned member and in communication with theoutput side of said valve,

*sarcasm prises, in combination, two coaxial rotarymem- .bers adapted to be driven one by therotherpcooperatingmechanicalzclutch elements carried by said -fmem'be'rs respectively,:onel ofrsald Vclutchfelements lbeing':movablyfcarried bythe .corresponding rotary member'transversely to `the'axis thereof so as to be retractable'vvithy respect'to :the path of travel of the other clutch element: and :being adapted "to be'urged towardiitsretracted position yby the eiortv transmitted theretoby-.theothel' clutch element, a` hydraulic jack Vincludinga cyl?- ind'er carried-at right angles Yto saidaxisbyithe same rotary member'as above 4mentioned,r-.apiston slidableinsaid cylinder 'and aA rod carried by `said piston adapted, in theexpanded position of said jack'to cooperate vvith.` the rst mentioned clutch element for keeping it in Working contact with the other clutch element, and a loaded disl, `chargeflvalve for said `jack adaptedi'ito -openin response to a'rise of the liquid pressure in'said cylinder abovea given value. f

8. A device of the type described which comprises, in combination, two coaxial rotary'lmlern'- bers' adapted'to beV driven one byftheother,l cooperating mechanical clutch elements carried by said members respectively, one'ofsaidclutch-elements consisting of a pawl p ivoted'toth' corresponding rotary member 'abvoutl an axis-:parallel to the rotation axis thereof so as to be retract'- able with respect to the path of travel of the other clutch elementA and being adapted-to be urged toward its retracted position by the effort transmitted thereto by the other clutchelement, a hydraulic jack including a cylinder carried at right angles to said axis by the same rotary member as above mentioned, a piston slidable in said cylinder and a rod carried by said piston adapted, in the expanded position of said jack to cooperate with the iirst mentioned clutch element for keeping it in Working contact with the other clutch element, and a loaded discharge valve for said jack adapted to open in response to a rise of the liquid pressure in said cylinder yabove v,a given value. l Y Y v 9. A device of the type described which com.- prises, in combination, two coaxial rotary members adapted to be drivenone by the other, co-

operating mechanical clutch elements carried by said members respectively, one of said clutch elements being moviably carried by the corresponding rotary member Vtransversely to the Y axis thereof so as to be'retractable With respect to the path of travel of the other clutch element and being adapted to be urged toward its retracted position by the effort transmitted thereto by the other clutch element, a hydraulic jack including 1a cylinder carried at right angles to said axis by the same rotary member as above mentioned, a pistonrsrlidable in said cylinder and a rod carried by said piston adaptedin the expanded position of said jack tocooperate with the first mentioned Yclutch element'for keeping it in working contactWith the other clutch element, a loaded discharge valve forsaid jack adapted to open in response to a rise yof the liquid pressure finesaidrcrlinderabove-ie; given-valsa .-anctmeans forgadj-ustingthe loadlof salddischarge .VVe 'd' '33 a 'a A; "1 J W1 .rf'lOz A eyice ofz-theetype-describedwhichcbgnprises; :inf'ifcombination-,xtwo: coaxial-:rotary membersfadapted: to bedri-venone bythe other, coop- :eratingfrmechanicalfclutch' elements-carried -by saidsmembers respectively', one-of.Y said clutchelementswconsisting-oiga paWl-pivoted-to the corresponding rotary fmember about -an axis 'parallel totherotation'axisf,thereof so as tor-be `retractable With'resp'ectfto thefp-ath-offtravel ofthe other -clutch'- elementffandfbeing v'adapted to be urged 'toward its retracted position :by-thel efforttransmitted thereto bythe other clutch element; ahy- `drauli'cA -j acls'` 'including a cylinder 'carried at right angles to 'saidaxisr byi the same rotary memberas above mentioned, a piston slidable inf said cylinder 'and fa-rod carriediby said tpistoniadapted',in the expanded position of said jack to cooperate with therst mentioned clutch element for keeping it in Working contact withthe other clutch element, a` loaded discharge valve for said jack adapted to open in response to la rise of the liquid pressure in'said cylinder-abovera givenfvalue, and

`meanslfor adjusting the load of said discharge valve. 'f

- l1. A device of the type described which comprises, in combination; two coaxial rotary members adapted to be driven one by theothencooperating' mecl'ranical` clutch elements carried by said membersrespectively, one of said'clutchelements being movably Ycarried by thevcorresponding rot-ary member transversely to the axis thereof so as to be retractable with respectto the path of travel of the otherfclutch element'and being adapted to be urged toward its retracted position by the eiort transmittedthereto by the other clutch element, an 'abutment' carried by the same rotary member for limiting the displacement of said rst mentioned clutch element in the direction corresponding to its projecting across the path of travel of the second mentioned clutch element, spring means for urging the first mentioned clutchv element toward said abutment, a hydraulic jack including a cylinder carried at right angles to said axis by the same rotary member as above mentioned, a piston slidable in said cylinder and a rod carried by said piston adapted, in the expanded position of said jack to cooperate with the iirst mentioned clutch element for keeping it in Working Contact with the other clutch element, and la loaded discharge valve for said jack adapted to open in response to a rise of the liquid pressure in said cylinder above a given value.

PIERRE LOUIS ANDR VERGNE.

REFERENCES CITED The following references are of record in the file of this patent: f

UNITED STATES PATENTS Number Name Date 1,388,311 Russell Aug. 23, 1921 1,485,987 Manvvaring Mar. 4, 1924 1,506,846 Lovejoy Sept, 2, 1924 1,797,407 Everstam Mar. 24, 1931 1,919,437 LeFevre July 25, 1933 2,293,786 Worden Aug. 25, 1942 2,293,787 Worden Aug. 25, 1942 

